COLD REGIONS ENGINEERING
"A Global Perspective"
March 7-9, 1994
Basic Considerations for the Structural Designer of Buildings Located in Cold Regions
M. R. Berretti
This paper is intended to give a general overview of the aspects of northern construction. It is proposed as a checklist for the use of structural engineers and, in particular, for those not very conversant in cold region design problems.
Norman Wells Air Terminal Building
K. Brown, B. George and G. Audette
This paper documents the structural, mechanical and electrical design challenges encountered during design of the Norman Wells Air Terminal Building/Flight Service Station, in Norman Wells, NWT. Special engineering solutions were needed to address: hydrocarbon contamination of the site; lateral earth loads; snowdrifting; challenging architectural features; extreme winter design temperatures; the impact of seasonal extremes combined with large quantities of building glazing; and other northern-specific challenges such as high energy and construction costs.
Design and Construction of Short Range Radar Stations in the Canadian Arctic
K. J. Sanderson
The Northern American Air Defence Modernization program consisted of construction of a new radar system to replace the Distant Early Warning Line (DEW Line) constructed in the 1950’s. Thirty-five unmanned radar stations were constructed along the northern Canadian coastline. Stanley Associates Engineering Ltd. provided engineering services for eight of these sites in Zone 2, which ranged from Coppermine to Gjoa Haven, NWT. This paper describes some of the design features of the foundations in permafrost, and construction aspects of the foundations and structures for each site. Each of the sites consisted of a radar tower, technical services building, two satellite ground terminals and a weather observation compound. Foundations for these structures are grouted, hollow steel piles in both permafrost soil and bedrock. Construction features of a typical site are presented.
Application of Canadian Design and Construction Techniques for the Canadian Village,
Republic of Sakha (Yakutia) Russia
C. Hostland, J. Clark, R. Abdurahman, G. Karst and B. Nelson
This paper focuses on the transfer of Canadian cold regions design and implementation knowledge through the medium of design and construction of a complete village for 150 people in the Republic of Sakha (Yakutia), Russia. As well, the means of modifying the Canadian approach to address a more severe climate, different language and social standards, and a somewhat different approach to Engineering skills and thoughts is contained in the discussion.
This region of the world suffers through extended periods of cold reaching minus 60 degrees Celsius or colder during winter months where the average daily temperature in January plunges to minus 47 degrees Celsius. Conversely, the summer can be stifling with plus 35 degrees Celsius temperatures not uncommon for July and August. Along with intermittent and warm permafrost conditions, a deep active layer and torrential rains in the fall of the year the site presented an extremely difficult and risky design and construction environment.
With the application of Canadian cold regions technology and general engineering expertise, this region experienced technical accomplishments in the following areas: the use of lightweight energy efficient wood and steel structure building envelopes; steel pipe piling installation as a primary foundation system; drilling water wells in permafrost; water treatment using reverse osmosis; packaged sewage treatment; use of upgraded mechanical ventilation; use of heated recirculating tanked potable and sanitary water systems for public buildings; optimization of envelope insulation levels and free air for occupancy based on cost and environmental efficiency.
The Use of Fresh Concrete for Piles in Permafrost
K. Senneset and T. Molmann
Fresh concrete was used in a laboratory study of model piles under the temperature conditions found in permafrost at Svalbard. In order to ensure concrete hardening and strength gain at low temperatures, additives to the concrete were used as well as an electric heating cable in the center of the pile. Tests were conducted in two different soils and at temperatures of -1°C, -5°C and -10°C. The results show that fresh concrete can be used for piles in permafrost either by using additives or by electrical heating in order to obtain required concrete strength.
Reinforcing Steel/Concrete Bond Strength Development in Concrete Cured
with Antifreeze Admixture at Temperatures Below 0°C
T. B. Wood and H. P. Schroeder
It is estimated that the cost of protecting freshly placed concrete in the United States from freezing damage is approximately $800 million annually. Chemical admixtures depress the freezing point of water and allow concrete to gain strength at temperatures which are below the freezing point of water. This study investigates the bond strength of the reinforcing steel and concrete in concrete cured at below freezing temperatures with an antifreeze admixture of sodium and calcium nitrite. Results indicate that concrete created with this antifreeze admixture and cured below 0°C will develop strengths comparable to concrete cured above 0°C without antifreeze admixtures.
Low-Temperature Admixtures for Concrete
C. J. Korhonen, E. R. Cortez, B. A. Charest and C. E. Smith, Jr.
Portland cement concrete cannot be cured in cold weather without some form of thermal protection. Optimally, concrete should be cured at temperatures between 10 and 20°C and at relative humidities of at least 80 percent, conditions rarely met in the field. Lower temperatures slow the hydration rate of cement, which delays strength gain and increases the amount of time before forms can be removed safely. If the temperature dips too low, the mix water will freeze, causing irreparable strength loss. The usual method of combating these undesirable low-temperature effects is to control the environment of the fresh concrete, keeping it warm until it can safely be exposed to the weather. An alternative approach to thermal protection is the use of chemical admixtures that help concrete to develop adequate strength at low temperature. This paper reports on a laboratory investigation and product development of various chemical formulations used as low-temperature admixtures. The experimental results show that these chemical admixtures are capable of promoting strength in cold cured concrete that meets today’s construction standards.
Strengthening of Marginal Soils by Confined Stone Columns
G. E. Bauer and N. Al-Joulani
The technique of stone columns or compaction piles to improve the mechanical properties of marginal soils is well established. In very soft soils these piles are difficult to construct due to the lack of lateral soil confinement. This paper proposes a new concept of providing additional confinement using sleeve reinforcement. An extensive laboratory investigation was carried out in which natural and reinforced stone columns were tested under controlled conditions. The experimental results are presented and discussed. It was concluded that sleeve reinforcement enhanced the physical properties of the columns and minimized their lateral bulging.
WASTE MANAGEMENT AND DISPOSAL
A Hazardous Waste Strategy for Communities in Canada’s Northwest Territories
R. J. Kent, G. W. Heinke, P. L. Heeney and W. J. Bryant
A hazardous waste problem exists in the Northwest Territories. The Government of the Northwest Territories recognized the need to manage known wastes in a manner that protects public health and safety, while maintaining environmental quality.
In 1990, a survey of business, industry, and communities was undertaken to determine the types and quantities of hazardous wastes and currently used disposal methods. The survey revealed some 2,500 tonnes of waste generated annually. In many regions of Canada, disposal of these materials may be routine, but the severe climate, expense of transportation, isolation, and small waste quantities provide problems requiring unique solutions.
In 1992, a hazardous waste strategy was developed. Plans would see community infrastructure upgraded to serve as transfer stations until sufficient quantities have been accumulated to justify a cost effective shipment to a disposal facility in southern Canada.
This paper will outline the steps leading to development of the hazardous waste strategy for Northwest Territories communities, discuss the results of studies undertaken, and describe how the strategy will be implemented.
Baling Facility for Municipal Solid Waste for the City of Yellowknife
D. Levert, I. MacLeod and R. Ellis
In response to a growing need for improvements and modifications in the waste management practices in Yellowknife, the City undertook a full scale study of the options available. Baling of Municipal Solid Waste (MSW) was selected as the most feasible for the area. The Yellowknife Baling Facility was designed as a prototype facility and is the first of its kind in the North and one of only very few in Canada. The design features a stepped structure utilizing existing terrain. There is an upper tipping floor over a lower baling and shipping area. The tipping floor features a heated floor slab to prevent freezing of wash water.
Effects of Leachates from Industrial Wastes on Soil Properties in Permafrost Areas
A. B. Lolaev, R. C. Joshi and G. Achari
High level of industrialization of northern regions, a typical characteristic of such areas, cause significant pollution problems in the soil. Sulphate salts in industrial wastes are a typical problem in Norilsk region of Russia. Experiments were conducted to study the rate of penetration of sulphate salt, into the soil during the freezing and thawing processes. Aqueous sodium sulphate salt solutions were added to the surface of a laboratory prepared sample before the beginning of the thawing processes. The time of thawing was kept constant. Three cycles of repeated thawing and freezing were conducted after each addition of salt. A total of ten salt additions were made and studied. This simulated about ten years of salt accumulation in the field. Physical properties and uniaxial compressive strength tests were conducted on the soil with concentrations of the salt varying between 0 to 150 parts per thousand. Uniaxial compressive strength tests were conducted at temperatures ranging between +20°C and -20°C. The test results indicate that the presence of salt significantly affect the physical and mechanical properties of the frozen soil. The depth of active layer increases with each addition of salt. The increase in the depth of the active layer is about 8.4 percent for ten additions of salt. Simultaneously, the temperature of the frozen section of the soil specimen also increases with each addition of the salt. Decrease in compressive strength, increase in depth of the active layer and increase in the temperature of the frozen soil will all contribute to the decrease of the bearing capacity of foundations in permafrost. It was concluded that estimation of salt concentration in the soil, and predictions of future increases of salt in the soil, is essential for design of buildings in permafrost.
HYDRAULICS AND HYDROLOGY
Stage-Frequency of Highly Variable Ice Jam Events
J. E. Zufelt and K. D. White
Stage-frequency analyses are typically conducted to assess the effects of the river improvements. Methods used to determine stage frequencies are based on either the historic records of actual stages experienced or stages synthesized from estimates of discharge frequency. Ice jam floods differ from open water events in that maximum or flood stages are often highly localized, resulting in ice effects being undetected by river stage gages outside the influence of the ice jam. The stages experienced during freezeup ice jams can also be highly variable from year to year. A method that calculates length frequency of freezeup ice jam events has shown to be especially useful for locations where ice jams may not occur every year.
Temperature Differences in the Restigouche Estuary During the Ice-Covered Season
C. Bettignies, A. St.-Hilaire and H. Dupuis
Thermographs moorings were placed under the ice-cover of the Restigouche estuary (New Brunswick) in order to monitor and quantify the influence of tidal action on temperature fluctuations. Temperature time-series show semi-diurnal variations of the order of 0.1°C. Temperature differences between surface and bottom are greater during the neap tidal cycle than during the spring tidal cycle. Time series of temperature differences were clearly modulated by both the semi-diurnal tide and the spring-neap cycle. Harmonic analyses show the predominance of semi-diurnal and spring-neap tidal constituents. These constituents cause a significant percentage of the temperature variations.
Temperature Effect on Flow in Sand-Bed Streams
F. N. Nnadia and K. C. Wilson
Laboratory and field studies have shown that a 9°C to 25°C reduction in temperature in an alluvial stream at constant discharge can effect relatively large changes in sediment discharge, roughness and bed geometry. The scope of this study was limited to the temperature effect on bed-load transport. This study elucidates the effect of temperature on flow and sediment transport characteristics of mobile sand-bed streams. As bed materials, sand of grain sizes 1.1 mm, 0.6 mm and 0.4 mm were used to simulate the mobile bed characteristics under varied flows using recirculating pressurized closed conduit system. It is concluded that water temperature variation can affect sediment transport under varied conditions.
Methods of Runoff Computations for Cold Regions in Modern Conditions
V. A. Lobanov
New methods of hydrological computations are offered for conditions of the modern climate change and human activity in the river basins and river channels. Methods include in itself: a choice of the dynamic indices, a building of mathematical models of historical time series, a hydrological computations of non-homogeneous time series in the conditions of different informational provision about hydrological data and its factors in cold regions, and also an estimation of a possibility of a super-long forecasts. Some case studies are considered.
Temperature Variation at Eighteen Canadian Weather Stations
Temperature records from 18 Canadian weather stations were analyzed in an attempt to show whether or note there is a warming trend evident in Western and Northern Canada. The stations chosen were all located outside major urban centres. Ten-year moving averages showed an increase in air temperatures in the period of about 1980 through 1940 with maximum temperatures being reached shortly after World War II. It was concluded that the evidence gathered in Western Canada was inconclusive and that further research is necessary.
URBAN AND ICE PROBLEMS
Global Ice Loads on Arctic Structures Interpreted from Foundation Displacements
K. J. Hewitt, K. P. Kennedy and P. J. Fitzpatrick
Bottom-founded caissons have been utilized for exploration drilling in the Beaufort Sea since 1981 in water depths up to 32 m. The design of these structures is dominated by the requirement to resist forces imposed by sea ice. The only reasonable method to derive global ice loads is from measurements and observations collected during full-scale interactions.
Over the past decade, significant research efforts have been expended in this area and as a result, global design ice loads have been continuously decreasing. From a geotechnical perspective, the response of the structure to ice loading is characterized by deformation of the foundation, which can be predicted using finite element modelling. The ice load can therefore be inferred from the measured deformation.
This paper presents eight histories in which foundation responses of Arctic offshore structures have been monitored and analyzed. In all cases, only small (if any) displacements have been recorded, suggesting that present design ice loads are likely still conservative. This data is compared and discussed with respect to other measurements and observations.
Ice Forces on Conical Piers - Numerical and Development of Design Equations
Over the years, Canadian design codes recommended various equations for the calculation of ice loads on conical structures. It is believed, however, that application of the design equations results in very conservative ice load estimations, and consequently there is room for less severe design regulations. In this paper, it is recognized that the complexities of ice-structure interaction problems dictate that the method of calculating ice loads on offshore structures should be numerical. A finite element study is conducted to examine the effect of ice floe size, ice thickness, and tensile strength of ice on the magnitude of ice loads. The results are used to develop a design chart and design equations for quick estimations of ice loads on conical piers.
Fire Protection Strategies for the Northwest Territories
C. Marianayagam and M. Michael
Fire protection raises some of the most challenging issues facing engineers and architects. Issues associated with fire prevention and suppression are complicated because of the complexity of not only the engineering, but also socioeconomic and political factors involved in the decision making process. Many stakeholders, players and regulatory bodies with overlapping jurisdictions are involved in providing and regulating fire protection practices. Various levels of government are faced with major capital and operation expenditures. And, because of the significant potential impact of fire protection decisions on property and life, this subject is politically sensitive, thus further complicating the decision making process.
In addition, it is virtually impossible to undertake cost-benefit analysis to guide expenditures or resource allocation to determine the most cost effective alternatives. Attaching prices or allowing for loss or risking human life is not acceptable when making such investment decisions. More investment may potentially reduce loss in property and life, but of course there are limited financial resources and last, but not lease, there is only one taxpayer.
In addition to challenges encountered in southern areas, northern conditions pose even more challenges and difficulties to all parties involved in the provision of fire protection. Most NWT communities are small, isolated and geographically scattered over a huge area. Community infrastructure is more susceptible to freezing due to permafrost and severe weather conditions. Most communities are on trucked water delivery with many buildings without pressurized plumbing systems. In addition, most communities have small populations and rely on volunteer fire departments. As a result, capital, operation and maintenance costs for fire prevention and suppression are very high in the NWT. Given these conditions, it is probably more cost effective and efficient to focus efforts on fire prevention rather than suppression; however, the latter appears to have been the focus of attention in the North.
Field Monitoring of Frost-Related Sidewalk Cracking
T. H. W. Baker, B. B. Rajani and W. G. Cooke
In October 1992, two sidewalk field test sites were constructed in Edmonton in a joint study with the City of Edmonton. Instrumentation to monitor ground temperatures, sidewalk vertical displacement, soil moisture, and soil pressure was placed beneath two new sections of concrete sidewalk located in the north and south sides of the City. Data acquisition systems collected hourly data on both sites. Monthly surface level surveys were carried out by the City of Edmonton. During the winter, the instrumented sidewalk section on the north side did not crack, but on January 20, 1993, a longitudinal crack was observed in the test section located on the south side. This paper presents some of the field data and describes the possible mechanism of failure.
This project is part of a larger laboratory and field program to determine the extent of the sidewalk cracking problem, to determine how damage is related to construction procedures, local climate and soil conditions and to develop effective solutions to minimize repair and replacement costs.
ROADS, AIRFIELDS AND PIPELINES
Study of Precipitation Rate on Holdover Performance of
Aircraft De-Icing and Anti-Icing Fluids
J. L. Laforte, P. R. Louchez, S. Bernardin and G. Bouchard
This paper describes an experimental investigation of protection time exhibited by anti-icing fluids under laboratory conditions simulating a supercooled precipitation. The emphasis is set on the influence of precipitation rate; temperature and surface angle effects are also examined. Six experimental fluids are used to represent all fluid types (I, II, III). As a major result of this study, a protection formula for protection time as a function of precipitation rate is given.
De-icing and anti-icing fluids used on aircraft on the ground are usually subjected to standard evaluation of their endurance to ice formation. There are presently two procedures which are performed in a cold chamber. These procedures intend to simulate frost and freezing rain conditions. A film of fluid is applied on a flat 30 cm x 10 cm aluminum plate, inclined at a 10 degree angle, and kept at a constant temperature (-5°C). Ice formation is induced by a cold (0°C), humid (96%) flow of air, for frost simulation, and by a spray of supercooled (-5°C) droplets, for freezing rain simulation. In these procedures, the time elapsed before ice formation is recorded to assess the candidate fluid performance.
The precipitation rates are 0.3 g/dm2h for frost simulation and 5 g/dm2h for freezing rain simulation. In general, the freezing rain case is taken as the major indicator of performance since it is the most severe physical process regarding fluid endurance to ice. Recent campaigns in airport fields in Europe and North America have shown actual precipitation rates, for freezing rain, range from about 0.5 g/dm2/h up to 25 g/dm2/h.
Roadway Management in Cold Regions: A Summary of Scandinavian Practice
F. L. Bennett
The Scandinavian countries have developed considerable expertise in the design, construction and operation of their roadway transportation systems. Two major asphalt pavement research programs have provided advances in the state of the practice. Specialized pavement designs include split mastic, drainage and, to a limited degree, rubberized asphalts. Various surface treatments provide solutions to dust control and surface stability problems on gravel roadways. Pavement markings adapted for cold regions include both extruded and sprayed-on thermoplastics. Ice control on pavement surfaces has, in recent years, featured reduced use of salts due to environmental concerns.
Evaluation of Pavement Layer Moduli for an Insulated Pavement Using
a Three-Dimensional Non-Linear Finite Element Analysis
M. A. Kestler, K. Stebbings, R. L. Berg, S. Zaghloul and T. D. White
A variety of methods exist for determining pavement layer moduli from Falling Weight Deflectormeter (FWD) testing. The most common technique, back-calculation, assumes that FWD loading is static, and most back-calculation programs assume that the pavement materials exhibit linear elastic behaviour. In contrast, ABAQUS, a three-dimensional finite element program, allows for the dynamic FWD loading and incorporates the nonlinear characteristics of the pavement materials. This more closely approximates the actual dynamic response and yields more realistic pavement layer moduli.
Although reasonable matches between measured and back-calculated deflections can be obtained using conventional back-calculation techniques, corresponding insulating layer moduli can vary over many orders of magnitude. Recent studies using ABAQUS to estimate pavement layer moduli from FWD measurements and to determine dynamic response to moving loads for non-insulated pavements have been quite successful. This paper discusses the use of ABAQUS to estimate pavement layer moduli and dynamic response for an insulated pavement.
An Experimental Section of Roller Compacted Concrete
Arterial Road in Edmonton, Alberta
H. A. Todres, P. Haug, A. P. Jacobs and T. J. McLaughlin
An experimental two-lane arterial road section was constructed of roller compacted concrete in Edmonton, Alberta in August 1992. The section is 550 m long, with a design thickness of 200 mm, and comprises a total area of 7,500 m2. Important information was obtained and more is expected to be derived over time with respect to pavement design, aggregate selection, mix design methodology, quality control and assurance, produce manufacturing techniques, placement and curing, strength development, cracking and crack skid resistance and the cold weather effects of frost and freeze thaw on the structure including surface wear caused by snow removal. This paper describes the design and construction processes, and the data gathering that has been performed to date. As the data collection is part of an ongoing process it will be appropriate to report on some findings at a later date.
A New Concept in Trail Grooming - "The KRC Groomer"
R. G. Alger
The concept of using snow as a building material has been studied internationally for decades. In particular, building roads and runways out of snow has been, and is presently, of major interest to researchers and industries that are involved in logistics in areas were snow depths make it necessary to travel on top of the pack.
KRC is in the process of developing a snow grooming system that was initially designed for use on snowmobile trails. This device is a result of research into the problem of mogul formation on trails and how to improve on present techniques to make the trail surface more durable. Studies have been conducted both in the lab and in the field in an attempt to better understand this bump formation.
The "KRC Groomer" is discussed along with some of the research that was conducted before the initial design. This devices is still in the early stages of testing, but does show great promise toward better methods of using snow as a paving material.
Initial Performance Permafrost Slopes: Norman Wells Pipeline Project, Canada
A. J. Hanna, J. M. Oswell, E. C. McRoberts, J. D. Smith and T. W. Fridel
The Norman Wells pipeline is a buried oil pipeline which traverses the discontinuous permafrost zone in northwestern Canada. The pipeline is operated at ambient temperatures, however, clearing of the right-of-way was sufficient to cause permafrost degradation. The route traverses numerous permafrost slopes consisting of ice rich clay that would become potentially unstable upon thawing. Wood chip insulation was selected as a means of retarding thaw on ice rich slopes.
Heat generation due to the decomposition of the wood chips was less than predicted except on about 15% of the slopes where more extended heat generation occurred, requiring some special remedial action. Several techniques have been attempted with varying success. Fore most insulated slopes, the wood chips have proven to be extremely effective in keeping the majority of the slope frozen. However, as the overland portions of the pipeline route warm up due to the surface disturbance and as oil throughput increases, the pipe temperatures have warmed up several degrees since the start of operation. The warmer pipe temperatures are causing some thaw around the pipe, beneath the wood chip insulation. On some, typically warmer slopes, the thaw bulb is extensive enough that there is a reduction in the estimated safety factor. As a result of this, about 10% of the insulated slopes were identified for a more detailed assessment of their stability. A probabilistic stability analysis has also been conducted.
Role of Heave Pressure Dependency and Soil Creep in
Stress Analysis for Pipeline Frost Heave
J. F. Nixon
A new computer program for pipeline stress analysis is described, and its application for predicting pipe deformations across differential frost heave and thaw settlement transitions is reviewed. The program solves the problem of an elastic-inelastic pipe, interacting with elastic-plastic soil springs. These soil supports can also creep according to a secondary creep law appropriate for icy frozen ground. Differential movements due to frost heave or thaw settlement can be applied to the pipeline. The applied frost heave can be specified to be pressure dependent. A very efficient solution technique is used, and a complete solution to a pipeline frost heave problem can be completed within a few minutes on a PC-486.
The new program has been used to solve some typical cases, and frost heave pressure dependency is included to determine the relative importance of this phenomenon in pipeline frost heave design. The effects of the shape of the uplift resistance-displacement function is also studied. Similarly, soil creep is included to study the affects of a reasonable range of this parameter on pipe strains and curvatures. Different soil types exhibit different amounts of pressure dependency in their frost heave characteristics, and therefore the importance of soil type in the resulting pipe strains is illustrated. Finally, the seasonal variation in pipe uplift resistance is included to observe the effects of seasonal relaxation in the uplift resistance on the pipe strains accrued over several years.
Engineering a 300 km Winter Haul Road in Canada’s Arctic
D. W. Hayley and M. A. Valeriote
This paper describes the planning, route location and preliminary engineering for a winter road from the proposed Izok mine in the central Northwest Territories to an arctic port on Coronation Gulf near Coppermine, NWT. The road will be a vital transportation route for hauling zinc concentrate to a deep water seaport and for transporting supplies to the mine. It will operate only in winter, with about 58 percent of its length across lake ice. Overland segments between lakes will require padding, using granular material to preserve the integrity of the tundra and increase operating speeds. Project specific guidelines will be required for operating the proposed triple-trailer trucks with nine or more axles over ice covers. Analyses were developed to accommodate multi-axle truck configurations without compromising safety that has been developed from experience with conventional highway trucks. Sufficient preliminary engineering has been completed for the route to prepare a cost estimate and construction plan.
Solving Sanitation Problems in the Alaskan Bush: Overcoming Socioeconomic Factors
J. A. Olofsson and H. P. Schroeder
Inadequate public health and sanitation facilities can be found throughout rural Alaska in spite of more than 25 years of concerted effort to provide sanitary infrastructure. Failure to achieve sustainable solutions is often perceived to be an absence of appropriate technology. Several conclusions are presented as a general outline for a multidisciplinary approach to solving sanitation problems.
Safe Water for Villages of the North Slope Borough
E. I. Shillington and K. E. Hansen
The North Slope Borough has made a commitment to supply modern water and sewerage facilities to all residents of the seven villages of the North Slope. The present water truck/"honey bucket" system presents a health risk to the residents and does not allow the use of water using appliances.
The approach taken to provide the needed sanitary facilities and the options evaluated for each village are described. Water consumption and sewage treatment requirements were developed and all seven villages were evaluated for the optimum systems. A budget between $240,000,000 and $300,000,000 over a seven year period will be required for full implementation. Conceptual designs, estimates and schedules are presented.
A Comprehensive Domestic Water Quality Study in the Northwest Territories
R. M. Facey and D. W. Smith
A comprehensive and unique water quality study was conducted for communities in the Northwest Territories from between 1990 to 1993. In total, the water supplies of 55 northern communities were sampled. The principle objective of the study was to identify both the quality of the source water and water supplied to consumers. Untreated and treated water samples were collected from each community and tested for chemical and bacteriological quality. Forty-three water quality parameters were measured for chemical characterization of the water supplies. Water samples were also analyzed for their relative corrosiveness using calcium and non-calcium carbonate based indices and examined for the presence of corrosion causing and corrosion intensifying bacteria.
Summarized in this paper are the results of this survey. In general, the quality of the water supplies for most communities, although based on a single sampling, are of good to excellent chemical quality. Only for a small number of communities did sampling their treated water reveal deficiencies with respect to the Guidelines for Canadian Drinking Water Quality.
Most water supplies are moderately to very aggressive with respect to calcium carbonate. From examination of the water quality data, it was found most are unsaturated, with many greatly unsaturated with respect to calcium carbonate. Corrosion causing and corrosion intensifying bacteria were also identified as being present in most raw water supplies in sufficiently high concentrations. However, the concern for corrosion for most communities is in regards to the deterioration of home plumbing and water storage tanks and by the health hazards posed by increases in metal concentrations, such as copper, in the treated water.
Insulation of Buried Water Lines in Cold Regions
W. H. Dilger, L. E. Goodrich, M. Pildysh and C. A. Humber
The paper presents results of experimental and theoretical studies of buried water pipes insulated with Granulite, an expanded shale or clay (lightweight aggregate) granular fill material. Twelve test sections with different geometry were instrumented to record temperature distribution, thermal conductivity and moisture content of soil and Granulite, intermittently, from 1988 to 1993.
Based on the experimental data two trench configurations have been developed for Calgary climate conditions.
The paper concludes with a discussion of the advantages for construction and with comments on the economy of the proposed new technology, as observed by the City of Calgary.
Forty Years in Frozen Ground - The Fairbanks Water Distribution System
In 1953, a unique piped water distribution system was installed in Fairbanks, Alaska. Other cities in cold climates relied on utilidors, bleeding, or dual main systems to keep water from freezing in mains and services. These options were considered during the design of the Fairbanks water system, but a newly developed technique using up and downstream facing pitot tubes (christened pitorifices) projecting into a single main and attached to dual service lines was chosen because of the substantial cost savings it promised. This paper describes competing designs, the history of the Fairbanks system, and recent field and laboratory studies on pitorifice and individual circulation pump performance.
Liquid Waste Management CFS Alert
J. A. Héroux, K. Biggar and S. Brasseur
CFS Alert was established in the mid 1950’s at the Northern tip of Ellesmere Island. Through the years, bulk liquids were airlifted to the station in 25 to 200 L (5 to 45 gallon) drums and liquid wastes were often stored in such containers. Approximately 2,300 of these containers were scattered around the station. Two years ago, a program was initiated by the Department of National Defence to remediate the problem. A liquid waste management strategy was also developed to prevent any future accumulation. In order to establish the contents of each barrel, an elaborate sampling and analysis program was implemented in the summer and fall of 1992. An environmentally sound disposal program was then established in accordance with the findings of the study. Most of the disposal was executed in the summer of 1993. This paper proposes to elaborate on the planning and operational procedures used to sample, analyze and dispose of the liquid wastes and briefly describes the essential details of the future management plan. The emphasis is placed on the conditions imposed by the location and the specific conditions encountered in this remote Arctic community.
Performance Evaluation of Primary Sewage Lagoon in Iqaluit, NWT
K. Johnson and J. Cucheran
Sewage lagoon systems in Canada’s far north are a fairly recent evolution in wastewater treatment, and comprehensive performance information is not readily available. Water licenses in the Northwest Territories stipulate submission of performance data on a regular basis, however in many instances this information is not collected.
UMA Engineering Ltd. was commissioned by the Town of Iqaluit in 1990 to provide preliminary engineering for the upgrading of the community’s primary sewage lagoon system. The purpose of upgrading of the lagoon is to meet the hydraulic and effluent requirements for the next 20 years.
As part of this preliminary engineering the Town of Iqaluit initiated a weekly sampling program of influent and effluent. These samples were analyzed for biochemical oxygen demand (BOD5), suspended solids, total coliforms, and fecal coliforms.
The lagoon produces significant seasonal variations in the effluent quality of suspended solids, BOD5, and fecal coliforms. The BOD5 and fecal coliform concentrations reduce significantly during the limited summer months, and the suspended solids concentration increases during the summer months.
Performance and Factors Affecting Performance of Lagoons in Cold Regions
D. S. Prince, D. W. Smith and S. J. Stanley
The performance of lagoon treatment in the Province of Alberta, Canada was evaluated and the factors affecting performance were analyzed. The evaluation was based on historical lagoon effluent quality from the years 1982 to 1992. The controlled discharge lagoons used in Alberta produce an effluent quality that is comparable and often superior to mechanical treatment alternatives. The factors that were demonstrated to affect effluent quality are season of discharge, month of discharge, storage time, and short retention cells. A cost survey of operating facilities showed lagoon treatment to be the least costly treatment alternative for communities of population less than 15,000.
Selection of Sanitation Alternatives: A Strategy for Remote Alaskan Communities
J. A. Olofsson and L. A. Iwamoto
Selection of appropriate wastewater disposal systems for rural Alaskan communities has been problematic. Many alternatives to water carriage systems exist and should enter the selection process but often do not for a range of reasons. Several alternatives are discussed here and a systematic approach to alternative selection is presented.
Monitoring and Remediation of Problems with the Buried Sewer System
in the Town of Iqaluit, NWT
A. J. Hanna and J. Cucheran
Problems have been experienced with access vaults, service connections and blockages of the HDPE pipe in the buried sewer system in the Town of Iqaluit. Design modifications were adopted to prevent water entering the insulated cavity of the access vaults and to prevent service connections from protruding into the sewer main. Most blockages in the sewer main occurred during the winter, however many blockages could not be properly cleared and were typically excavated the following summer. Pipes were found to be collapsed to varying degrees. Preliminary information suggested the cause was external squeezing of the pipes, probably due to excess pore pressures developed during freezeback of the active layer. Monitoring of temperatures and pore pressures during freezeback was undertaken. The possible influence of variable snow cover was assessed by observing snow conditions at pipe collapse or oval locations that had been observed with a sewer camera. Initial remediation measures have shown that board insulation placed over the mains can, under certain conditions, thermally stabilize the pipe zone once the initial freezeback has occurred.
Effects of Freeze/Thaw Cycles on Hydrocarbon Contaminants in the Active Layer
M. A. Cummings, M. A. Tumeo and T. Tilsworth
As part of a study of the movement of hydrocarbon contaminants in ice and frozen soil, researchers are seeking to determine the effects of freeze/thaw cycles on the behaviour of diesel fuel in the active layer. Diesel was chosen as the contaminant because of its widespread use and importance as heating and engine fuel in the polar regions. Other physical processes governing movement in non-frozen porous media will be held constant in a carefully controlled environment in order to isolate and examine the effects of freezing and thawing on contaminant migration. Field studies in the Arctic and Antarctic will be used to corroborate lab studies. A review of relevant literature and experiment methodology will be presented at the conference along with slides and data from January 1994 Antarctica field study.
Low Temperature Kinetics of Anaerobic Filter Treatment of Wastewaters
R. Varadarajan and T. Viraraghavan
The effects of liquid temperature and hydraulic retention time (HRT) on treatment efficiency in the anaerobic filter process were examined based on laboratory studies on septic tank effluent and dairy wastewater. Three anaerobic filters were operated at 5, 10 and 20°C treating septic tank effluent at different HRTs (1.20, 2.38, 3.17 and 4.76 d), while three anaerobic filters treating dairy wastewater were operated at 12.5, 21 and 30°C at HRTs of 1, 2, 3, 4 and 6 days. The treatment efficiency of the anaerobic filter process was affected by temperature and HRT. The anaerobic filter operated at a higher temperature performed better than those operated at lower temperatures. It was found that the filter operated at a lower temperature was the most affected by the changes in HRT. Kinetic parameters are presented for various temperature conditions and the effect of temperature is analyzed using the Arrhenius’ equation.
Operation and Performance of Sludge Freezing Bed at Fort McCoy, Wisconsin
C. J. Martel
The first sludge freezing bed was constructed in 1989 at Fort McCoy, Wisconsin. This bed is 20 m long by 10 m wide and has a capacity of 214,000 L at a design freezing depth of 1.2 m. During the first winter of operation it froze 0.91 m of sludge from the plant’s anaerobic digester. After thawing and drainage, only 50 to 80 mm of solids remained in the bed. The total solids content of this material was 78%. The total solids content of the applied sludge was 4.7%. Odours were not a problem and return of the meltwater back to the head of the plant did not upset the treatment processes. The operators of the plant were very pleased with the performance of the bed and the relative ease of sludge removal.
The Operation and Monitoring of Sewage Disposal by Stack Injection
D. A. Jensen
The treatment and disposal of sewage in the Arctic is often difficult and expensive. It is difficult to use leach fields because of permafrost, and it is expensive to purchase and operate sewage treatment plants for small work camps or villages. Since 1977, Alyeska Pipeline Service Company has utilized turbine exhaust to evaporate the sewage at those Alyeska pump stations located in permafrost areas. The pumps moving the crude oil in the Trans Alaska Pipeline System (TAPS) are driven by simple cycle gas turbine engines which produce large amounts of waste heat. The waste heat can be used to evaporate the sewage effluent, thereby destroying all the pathogens in the sewage. This process, known as "stack injection", was recently upgraded to increase efficiency and safety. Stack injection is currently being used at five TAPS pump stations. This paper reviews the field data used to redesign the system and discusses the methods used to control the operation of stack injection to maintain public health.
PERMAFROST AND FOUNDATION ENGINEERING
Pile Load Test on Large Diameter Steel Pipe Piles in Timan-Pechora, Russia
S. McKeown, B. Tart and R. Swartz
This paper describes pile load testing conducted in May and June of 1993 at the Polar Lights Ardalin project in Arkangelsk province, Russia. The pile load testing was conducted to determine the ultimate and allowable pile loads for varying pile lengths and ground temperature conditions and to provide creep test data for deformation under constant load. The piles consisted of 508 mm in diameter steel pipe piles driven open ended through prebored holes in the permafrost soils and were allowed to freeze back for a minimum of seven days before load testing.
The Compilation of Geotechnical Information from the
Short Range Radar Sites into a Public Domain Database
K. W. Biggar and P. Hoang
The Short Range Radar project involved the construction of 36 unmanned radar sites across the Canadian Arctic and along the Labrador coast. Foundations at the sites used pipe piles grouted into permafrost soils or rock. Upon completion of the construction, the site geotechnical data were forwarded to Royal Military College for compilation into one comprehensive computerized data base. The data base information includes stratigraphy, soil temperature profiles, pile design and installation information, pile test results, and grout curing performance. In addition to being useful for the site managers, the information will be useful for pile performance case studies, mapping, etc. It is intended to make the data base available to the public.
Design, Construction and Operation of an Insulated Ice Drilling Pad, North Slope, Alaska
B. Hazen, D. L. Miller, M. J. Stanley and W. S. Powell
In the fall of 1993, BP Exploration (Alaska) will begin drilling the Yukon Gold exploratory oil well off of a 10,670 m2 (2.6 acre) ice pad. The pad had been built the previous spring and had been insulated with reusable, pre-fabricated, foam-core panels to arrest melting of the ice and active layer during the summer. To minimize environmental impacts and site development and restoration costs, the pad was built directly upon the undisturbed (frozen) tundra and there were no excavations. Building the pad in the spring so it was ready to be occupied and used early in the fall added approximately 50% to the length of the 1993/1994 drilling season.
This paper discusses the design, construction, and geothermal performance of the insulated pad. Ice surface temperature data collected by on-site data loggers are compared to finite-element model predictions. Recommendations are given for improving the design and for using similar designs to extend further the Arctic drilling season.
Freeze-Thaw Dewatering to Reclaim Oil Sands Fine Tails to a Dry Landscape
D. C. Sego, R. F. Dawson, T. Dereniwski and B. Burns
This paper presents freeze-thaw dewatering design concepts for oil sands fine tails. Design models are presented, based on recent laboratory and field data, that quantitatively outline the volume separation and strength development associated with thin layered freeze-thaw dewatering management strategies. The design calculations using these models predict that reclamation of the fine tails to a dry landscape is viable.
For the existing oil sands operations analysis shows that it is possible to freeze more material than will thaw. Thermal calculations show that up to 3.0 m/yr. of frozen fine tails can be thawed under ambient conditions in Fort McMurray while up to 4.5 m/yr. of frozen fine tails can be thawed when a warm wastewater cap is used. Volume separation approaching 70% are estimated after five cycles of yearly placing, freezing, and thawing.
A prototype field freezing experiment is described and it is shown that 60% volume separation occurred after one cycle of freeze and thaw. The dewatered fine tails are capable of being reclaimed since the surface will support human activity. The volume separation after freeze thaw in the field test is significantly greater than could be predicted. This suggests that the slow natural thawing enhances the volume separation process.
Highwall Stability in Strip Mines in Permafrost
The instability of highwall slopes, exposed to thawing, in surface coal mines in permafrost regions is described. Remedial measures are proposed to prevent shallow as well as deep slope failures in these regions. A practical design configuration, which involves introduction of a wide bench at the bottom of the permafrost layer, is proposed to mitigate highwall instabilities.
Cone Penetration Strength of Saline Silty Permafrost at
Kangiqsualujjuaq, Nunavik (Quebec)
R. Fortier, B. Ladanyi and M. Allard
During the thaw period in 1992, a cone penetration test (CPT) program was carried out in a silty permafrost mound at Kangiqsualujjuaq, Nunavik (Quebec). The principal objective of this project was to define the influence of the physical properties of permafrost on its strength.
Eight series of four CPTs in separate holes and one core sampling per week were performed over a two-month period to determine the stratigraphic profile and the penetration rate dependence of strength, and the physical properties of permafrost.
From the numerical analysis carried out on the results, the strength of permafrost has been found to be linked to the temperature and salinity. The simultaneous influence of these last two parameters could be combined in the unfrozen water content parameter. The relationships found between point resistance and these parameters depend on penetration rate and total water content.
Dynamic Strain Characteristics of Saturated Frozen Silt
He Ping, Zhu Yuanlin, Zhang Jiayi and Wu Ziwang
A series of vibration tests were conducted on saturated frozen silt at constant dynamic loading parameters (maximum stress, minimum stress, frequencies, temperatures). The test results indicated that dynamic elastic modulus decreases with increasing strain, the strain is influenced strongly by the vibration frequencies and maximum stress. The failure strain increases with the maximum stress increasing and frequency decreasing (the frequency ranges are from 0 to 20 Hz). The failure time is shortened with increasing frequency. Dynamic creep can also be classified into two types, i.e. attenuated and unattenuated creeps. The creep rate accelerates with increasing dynamic stress. The dynamic creep model is presented in the paper.
Calculation of Frost Heave in Saturated Soil Under Constant Surcharge
Based on an assumption that moisture migration occurs only in the freezing fringe, a simple method for the calculation of frost heave is proposed. Using the simplified calculating method, the processes of frost heave for two experiments are calculated. Comparing the prediction with the test data, it is found that the calculated results of frost heave and moisture field are similar to observed data. The calculations for different surcharges show that the frost heave ratio decreases with the increase of surcharge by an exponential law, which is analogous to some empirical formulas. The proposed method is expected to be used for the prediction of frost heave in field due to its simplicity.
The Simulation on Thaw Consolidations of Saturated Frozen Soil
Ma Wei and Wu Ziwang
Using a coupled model of heat, mass and stress which combined with equation of damage, a numerical simulation of process of thaw consolidation in saturated frozen soil was carried out. Compared with test data of consolidated light loam in Daqing, it is found that the maximum pore water pressure locates nearby the thawing interface and decreases with an increase in time. The maximum displacement appears at surface of ground and tends to a stable value with an increase in time. Meanwhile, it is found that the effective stress nearby the thawing interface is very small, this will result in a decrease of shearing strength of soil and firstly cause damage nearby the thawing interface.
Performance of a Water Retaining Dyke on Discontinuous Permafrost Foundations
R. J. Wittebolle and B. B. Dickinson
The Long Spruce Generating Station, located in northern Manitoba, required the construction of water impounding dykes on permafrost affected foundations. The sand fill dykes range in height from 1 m in the freeboard section to an average of 9 m at the intersection with the main dam. Sand drains were installed to assist drainage of the thawing foundation. To predict the anticipated thaw settlements, laboratory thaw consolidation testing was conducted on representative soil samples. Actual field settlements and pore pressure responses were monitored at three test sections after construction. Good correlation was found between the predicted and measured settlements. Excess pore pressures in the foundation were quickly dissipated by the sand drains.
Demonstration, Analysis and Development of Frost Protected Shallow Foundations
and Freezing Index Climatography for Residential Construction Applications
in the United States
J. H. Crandell, P. M. Steurer and W. Freeborne
Several years of research and technology transfer has culminated in the development of design guidelines for frost-protected shallow foundations (FPSF) in the United States. Tasks have involved estimation of 100 year return period freezing indexes, computer analysis of ground heat flow around insulated building foundations, field demonstrations of European FPSF design strategies, field data acquisition, and performance analysis of actual FPSFs. Data from over 3,000 weather stations have been analyzed to provide a statistical representation of the air-freezing index for the United States. From this effort, a climatography of 100 year return period air-freezing index has been created for the U.S. (including Alaska). Differences in estimating air-freezing indexes have also been compared between methods used in the United States, Sweden and Norway. While summarizing FPSF developmental efforts in the United States, this paper reports recent work on air-freezing indexes to verify suitable probability distributions from select long-term weather records.
About an Assessment of Factors in Railway Bed Stability in the Permafrost Zone
L. S. Garagulya and Ye. N. Ospennikov
The important results of field observations made within the central section of the Baikal-Amur railway providing an explanation for the causes of the railway bed deformations are considered in this paper. The data obtained have allowed to make a number of methodological recommendations concerning surveying and designing of railways in the southern permafrost zone as well as to put forward some approaches to ensure railway bed stability within the railway section under operation.
Cryogenic Deformation in Soils and Their Engineering Geology Consequence
I. D. Danilov and V. E. Roujansky
Cryogenic soil deformations are of widespread occurrence within the Arctic and Subarctic regions composed of thick fine-grained frozen sediments. Three types of cryogenic deformations, namely, cryogenic-lithogenic, cryogenic-disjunctive and cryogenic-plastic ones, are considered. Different mechanisms of their formation are shown. The diversity of cryogenic deformations and their morphological resemblance to the tectonic dislocations suggest a specific type of the exogenic tectogenesis, namely, the "cryogenic tectogenesis". The investigations of these phenomena are of practical significance.
Experience of Preliminary Engineering - Geocryological Investigations in the Oil and
Gas Bearing Regions in the North of Russia
E. S. Melnikov and A. V. Pavlov
A complex of in situ engineering-geocryological investigations, carried out in the oil- and gas-bearing regions of the Russian North, includes engineering-geocryological (or combined with hydrogeological) surveying and geocryological monitoring. The methods of these investigations are based on a landscape approach. Scales of surveying and detailedness of observations at the monitoring points fully depend on the stages of geologic-exploratory works.
Formation, Distribution and Dynamics of Cryopegs, and Associated Problems
of Construction North-West Yamal Peninsula, Russia
I. D. Streletskaya
Experience in construction in the North-West of the Yamal Peninsula shows that cryopegs are widespread phenomena which influence negatively upon base of foundations. Cryopegs are bodies of liquid saline water below associated with permafrost, and may also imply ice-free permafrost with saline pore water. Cryopegs are corroding metal and concrete underground structures. Cryopegs prevent adfreezing of piles with soils. Of special interest is the cryopegs that are present at shallow depths in the zone of interaction of saline waters and foundations. A map of cryopegs distribution for North-West Yamal could help to solve some problems of construction in this region.
Evaluation of Interaction of Buried Chilled Pipeline with Soils in Taliks
Using Thermodynamic Model
S. E. Grechishchev
When gas chilled up to a negative temperature is transported by a buried pipeline at the place of crossing with below water-bed taliks, there is a danger of frost heave of freezing soils around the pipe. The thermodynamic model of cryogenic moisture migration and heaving in freezing soil proposed earlier by the author has been used to calculate maximum heave pressure ("shut-off pressure"). Temperature field is assumed to be independent of mass transfer. The evaluation shows that for silty and clayey soils the shut-off pressure depends upon the thickness of frost bulb and can be very high. The negligible heave pressure occurs in sands.
Engineering and Geocryological Problems of the Development in the North of Yamal
V. V. Baulin and A. L. Chekhovsky
This article considers specific engineering and geocryological conditions in the North of Yamal (saline ice content soils, underground massive ice, cryopegs, cryogenic processes) which need special project solutions to provide the stability of structures. The construction in such conditions should be made with due regard for the permissible nature of disturbances and environmental protection.
Experience and Primary Tasks of Geocryological Studies for Russian Railways
V. G. Kondratjev
Hundred years of experience of geocryological ensuring of main lines in Russia is analyzed. The target and methodology of geocryological investigation for survey and operation of main lines is characterized. Results of geocryological observation and monitoring of Bajkal-Amur Main Line (BAM) roadbed are set out. The main proposition on designing of roadbed and small artificial construction of constructing Amur-Yakutsk Main Line (AYM) are elucidated. The proposition envisage anti-deformation measures, including pilot-experimental ones, based on new inventions. BAM and Transsib Main Lines tasks are formulated. A lot of attention was attracted to geocryological ensuring of proposed Transcontinental Main Line from Siberia to Alaska.
Problems of Providing the Optimum Interaction Between a Hydraulic Structure
Foundation and Its Environment in Cold Regions of Russia
A. L. Goldin, A. A. Kagan, N. F. Krivonogova and D. D. Sapegin
The paper considers intricate processes related to the interaction of hydraulic structures and the geological deposition medium in the regions with natural conditions of high instability explained by the abundance of permanently frozen soils. Different lines of attack on the problem of the optimum interaction between a structure and its geocryological medium are illustrated by specific examples of hydraulic structures constructed in Northern Russia. The methods used are based on the model of the geological engineering medium protection.
Subsea Permafrost and Gas Pipeline Construction of the Baydaratskaya Bay
Crossing in Siberia, Russia
G. I. Dubikov, N. Figarov and A. Tsourikov
The present paper deals with the problems of subsea permafrost and gas pipelines construction at shore sites and under bottom of Baydaratskaya bay (Kara Sea). It discusses the new data about composition, temperature, thickness and ice content of subsea frozen grounds and relationship of the frozen ground and cryotec soils with temperature and salinity of the bottom grounds.
Cryogenic Landslides and Their Interaction with Linear Constructions
on Yamal Peninsula, Russia
M. O. Leibman
Cryogenic landslides (CLS) in the Arctic are the most widely spread among the periglacial processes and territories of their activity and the most risky for construction use. Linear (especially railway) construction on Yamal Peninsula entails great difficulties connected with interaction of moving CLS matter and embankment.
Three types of interaction and corresponding mathematical models can be marked out: (1) embankment is above the unstable slope and CLS can damage its foundation, (2) embankment is at the foot of the hill and CLS can displace, destruct, or cover the embankment, and (3) the embankment crosses the slope so that above and below it both 1 and 2 types occur.
The maximum size of CLS unable to damage the embankment is calculated. Established regularities in size and localization of CLS makes it possible to map unstable slopes with the potential CLS size exceeding the calculated maximum.